Subject is D-6411, female, 32, average physique. Subject's background shows an incident of attempted murder. Subject is equipped with standard mission equipment pack and sent into SCP-432. Camera is activated and subject enters SCP-432. The door is held open by a 3kg weight placed inside the doorway, with technicians on hand to remove the weight and close the door if required.

Camera activates, showing subject is in a long corridor constructed from the same corroded metal as the exterior of SCP-432. Light from the open door behind the subject, coupled with the illumination provided by the bulbs located at irregular intervals on the walls of the structure, lights the tunnel for approximately 20 meters. More lights are visible further down the tunnel, but are very dim. Control requests subject turn on her torch and move into the structure, subject complies.

The passage continues for approximately 100 meters from the entrance until it ends in a t-junction leading left and right. Subject asks Control which way to go and is told to go right. D-6411 marks the route back to the exit with marker chalk and proceeds down the tunnel for 50 meters until a cross-roads is reached. Control informs subject to take the left-hand branch and subject marks the tunnel wall and enters the indicated passageway, which is followed for 47 meters until another cross-roads is reached. Control notes interference to both the video and audio feeds has begun to appear, but is currently negligible.

Subject pauses to drink from one of her bottles of water and marks her route back before selecting -without permission from Control- the right-hand branch. Control admonishes D-6411, but allows her to continue. The passageway makes a 90 degree turn left after 18 meters, then continues straight for approximately 73 meters.

Ahead of the subject appears another cross-roads, but as the Subject nears it she freezes and reports that she can hear a rhythmic banging coming through the walls. Control boosts audio gain on camera and the sound is picked up. The banging lasts for 73 seconds before it stops. Subject has remained still while listening, attempting to breathe quietly. Control prompts the subject to mark the tunnel wall and proceed left. The subject remains motionless and makes several enquiries into the nature of SCP-432 and the source of the banging. Control firmly reiterates their commands and Subject resumes walking, taking the left tunnel as indicated.

Subject has travelled for almost 150 meters when she stops and aims the camera at the left wall of the tunnel. She observes that all of the light fittings in this stretch of the structure have been broken; shards of broken bulb are visible scattered across the floor. Subject continues forward, remarking that she has begun to detect a faint, unpleasant odor. When asked to describe said odor, D-6411 replies "Something dead".

After a further 24 meters the Subject notices an object in the tunnel ahead and moves towards it. Video quality is now beginning to severely degrade. Camera angle tilts as Subject kneels to examine the object, and Control asks Subject to explain what she has found. Subject explains the object is a left sports shoe, commonly known as a ████████ sneaker. The camera zooms in on the object while the Subject illuminates it with her light source.

Camera view tilts again as Subject suddenly looks down at the floor of the tunnel and emits a loud expletive. The floor of the tunnel is covered with a large quantity of dried brown residue that crackles and flakes as the Subject moves her feet. Sprays of the residue are observed dried onto the walls. The Subject remarks that the substance is apparently the source of the odor, and she surmises it is dried blood. The camera tracks several large smears of the substance leading away from the pool up the corridor. Subject's breathing is becoming slightly panicked.
Control requests the Subject collect the shoe and a sample of the substance for analysis. Subject does so, although complains continuously about the smell and expresses wishes to exit SCP-432. Her requests are denied and Control orders the Subject to continue onwards.

Subject continues down the corridor at a much decreased walking speed, and is becoming agitated. Camera view changes repeatedly as Subject begins looking over her shoulder at erratic intervals. Video and audio feed are beginning to become severe and Control asks Subject to halt while they confer with Dr █████.

Dr █████ decides to recall the subject, who is now becoming extremely panicked, complaining of hearing footsteps behind the wall to her right. Control boosts audio but interference prevents confirmation of Subject observations. Dr █████ confirms the expedition is over and Control recalls the subject, who begins moving back towards the exit at increasing speed.

Subject's egress from SCP-432 is unremarkable except for Subject's increasing speed as she nears the exit. Once out of SCP-432 the door is closed and locked and Subject sent for debrief.